Glass protector for reflectors



May 4,1926.

B. BART GLASS PROTECTOR FOR REFLECTORS Filed Jan. 11, 1923 INVENTOR 1515.55 us Ba 1" i" ATTORNEYS Patented May 4, 1926.

' rumTEo STATES lfi8 e f;

PATENT OFFICE.

IBLASIUB BART, OF EAST ORANGE, NEW JERSEY.

oLAss rnorncron won numerous.

Applicationnled January-11, 1923. Serial No. 612,131.

To all whom i2, may concern.

Be it known that I, BLASIUS BART, a citizen of the Republic of Switzerland, and

resident of East Orange, in the county of 'Essex and: State of New Jersey, have invented ,certain new and. useful. Improvements'in Glass Protectors for Reflectors, of which the following is a specification.

The invention relates in general to reflectors and more particularly relates to a guard for protecting the reflecting surfaces of reflectors. More specifically defined the invention relates to a combined metallic reflector of the type generally known as a parabolic reflector, together With a glass guard for the same, fabricated to form av single unitary article of manufacture designed to be mounted in; a suitable frame to form a lamp.

Accordingly the primary object of the invention is to provide a simplified ineans for protecting a reflecting surface which pro- Another object of the invention is to pro vide a combined reflecting element. and a guard therefor which will provide a means for mounting an electric .light carrying socket or similar means for mounting the source of light and without necessarily providing separate parts for this purpose.

Various other objects and advantages of the invention will be in part obvious from a consideration of the method features of the disclosure and from an inspection of the accompanying drawings and in part will be more fully set forth. in the following par-.

ticular description of one method of prac ticing the invention and one form of mechanism embodying the mechanical features of my' invention and combination of parts hereinafter set forth and claimed.

In the accompanying drawing the fi gure is a view in axial sectiontaken through an 3 article of manufacture," including a" re ect'or surface 12 eorrespondin' 7 type of. reflectors and 'a guard therefor, co-acting to constitute a preferred embodiment; of .the invention and lllustra-tlng a complete lamp.

In the drawin there is shown a thin metal shell 10, which'includes a curved por- 0 tion 11. having on its inner face a reflector 1n general to the enera 1y known as parabolic reflectors. or the purpose of illustrating the invention in connection with a 05 readily destroyed reflecting'surface, it will be understood that the surface 12 is athin' layer of silver deposited electrolytically on a suitably shaped mold. As this reflecting layer is so frail that normally it is not of suflicient strength to maintain its own con-' figurat1on, there.1s dlsclosed a reinforcing backing 13 of copper preferably also d e,

posited by an electroplating operation, all

as is well known in a method of producing silvered metallic reflectors.

The copper backing is provided with a'tul bular extension 14 which projects outwardly from the crown of the curved portion of the shell. The outer free edge 15 of the copper backing is provided with an annular recess 16 designed toform a seat for the. guard 17 hereinafter more fully described. It will be understood that the reflector as thus far described is of well-known form and it is required that the reflecting surface be formed exactly to correspond to some desired configuration. Usually this reflecting surface is formed with the mathematical accuracy characterizing the formation of optical in- 00 struments.

The guard 17 includes a part 18 which conforms substantially to and extends across the reflecting surface from the shoulder 16 to the point of conjecture of the curved portion of the backing with its extension 14. It is a feature of this disclosure that the surface 18 need not be formed with any degree of accuracy. It will be a usual practice to blow the same into theform ofa thin glass shell we so that it will conform in rough outline to the configuration of the curved portion of the reflecting surface, and of course with the 1 size sufliciently less than the dimensions of the reflecting surface so that there will be a rough telescopic fit between the reflecting surface and the guard. 'From this disclosure, it willbe understood that the guard need not physically touch the reflecting surface andPrQferabIy the glass guard is low no to such size that there-will be a shallow air space 19 between the reflectingsurface and its guard.

,Advantage is taken of this airspace to provide a heat insulator between the source of light, indicated by the lamp 20, and the reflecting surface. I For the purpose ofse'al ing this airspace, the glass guard is providjed with an extension 21. formed integrally at this point, but-it is within the scope of therewith and. having a' snug telescopic fit in the metallic extension 14. Usually, it will not be necessar. connection. between t e glass and-metal shells this disclosure to hermetically seal the extensions inorder to defeat any ossibllity of air leakage into the air space. tits free edge,22,"the glass guard is provided with an outwardly extending integrally formed flange 23, which has a more orless accurate 7 fit on the seat 16. Usually it will be necessary to provide a hermetic seal between the; glass flange and its seat audit is herein suggested that asprayof metal 24 be inserted between the-flange and itsseat.

to otherwise seal the- Having thus described my invention, I

claim: v r

A lamp comprising a-thin metal shell including a curved portion having on its inner "face a parabolic reflecting surface of elec- Q trolytically deposited silver and being incapable per se of maintaining its configurationy, acopper'. backing for the silver surface,

.said backing provided with a tubular ex-y tension projecting outwardly from the 35 crown of the curved ortion of the shell, the

outer free edge of t e copper backing provided with an. annular recess, a glass guard having acurved port conforming substani tially to the silver reflecting surface, said 40 guard provided with an integral extension having a snug "telescopic fit inthe metallic. 

